1. Field Of The Invention
This invention relates generally to the field of building construction and more particularly to devices used to support and fasten architectural panels together to form the exterior of a building.
2. Brief Description Of The Prior Art
Complex fastening and support systems used to connect exterior aluminum facia panels together to form the exterior of commercial buildings are old and well-known in the art. As it is extremely expensive to construct commercial office buildings from brick, and wood is unsuitable for this type of construction, the commercial industry has turned to the practice of employing large sheets of architectural panels made of aluminum, steel, masonry or even large glass panels to form the exterior surface of a building. Because of this extensive utilization of exterior panels, a variety of different types of connecting brackets have been developed over the years to serve as means for fastening these panels together while also forming a sturdy support structure therefor. However, the fastening systems presently known in the art have many inherent problems or shortcomings.
Some of the prior art problems are as follows. First, the fastening systems presently known in the art tend to be overly complex in structure and composed of many small pieces susceptible to easy loss or damage. Secondly, those systems presently known in the art are not particularly effective. The seams and joints tend to leak when exposed to rain. This is such a major problem that the corners where four panels meet usually form a square void which must be filled with a caulking material, such as structural silicone. Caulking has a limited effectiveness due to its very nature, is very time consuming to apply and is not a very reliable sealant especially in a metal to metal joint wherein the metal components expand and contract in response to weather or other atmospheric conditions. These panels are also exposed to wind velocities which shake the panels and tend to break the caulk joints/seals no matter how carefully they have been applied thereby ruining their effectiveness in a sealant capacity.
Another major problem with the prior known fastening systems is the manner in which these panels must be applied to the exterior of the building. Namely, when the prior art fastening systems are employed to secure panels to the exterior of a building, the panels must be installed in a progressive sequence--i.e., bottom-to-top and right-to-left (or vice-versa) sequence, along each face of the building. If a panel in the middle of a wall is incorrectly installed or subsequently damaged, all of the panels from the edge of the wall back to the damaged panel must be removed in reverse order in order to replace the single damaged panel. This is not only a waste of construction time but it inherently exposes the undamaged panels to damage themselves by having to remove them once set.
The fastening system marketed by Architectural Product, Inc. of Willoughby, Ohio, is an example of the prior art widely used in this field. A typical bracket is comprised of a modified T-shaped bracket wherein the side of the T exposed to the exterior is very short in width and provided with a vertical flange that seats within a groove provided along the edges of the architectural panel. The straight of the T rests against the length of the panel with the end thereof either resting freely against said panel or provided with: a sealant along the edge thereof. The other side of the T extends back to form a connection with a bracket that has been bolted to the exterior wall of the building. The point at which the T attaches to this bracket may comprise a channel connection which is also provided with a sealant. The gaps (usually on the order of 1/2 inch) extending along the joints between each adjacent pair of panels are filled with additional sealant and a backer rod therefor. It should be noted that both the horizontal and vertical joints have the presence of these large gaps between every pair of adjacent panels when utilizing this panel fastening system. In addition, these gaps form square voids at each panel corner which are especially difficult to fill with sealant so as to prevent leakage of water behind the panels. An alternate fastening system employs a complicated U-shaped bracket that is attached to a main support bracket which is in turn supported by a third bracket fastened to the stud wall. In this instance, three different brackets must be interconnected to support the exterior wall panels. Gaskets, urethane sponge weeps and sealant are provided within the bracket-to-bracket connections to try to make these connections fluid tight. However, owing to the fact that numerous connections are made, and that the brackets must be carefully assembled together, there is a tendency for joint leakage to occur and for the brackets to be susceptible to breakage when exposed to external weather conditions.
The closest prior art is the "ALUCOBOND" wall system marketed by Elward, Inc. of Lakewood, Colo. In this system, the bracket extending along the bottom edge of each panel has a modified T shape, with the short side of the T provided with a flange that fits within the groove provided along the bottom edge of the architectural panel. The straight of the T fits flush against said back of the panel adjacent to the bottom edge. The other side of the T is provided with an inverted U-shaped channel which accommodates a vertical member extending upwardly from the bracket extending along the top edge of the panel below which has been secured to the wall. The inverted U-shaped channel has been provided with two opposed wipers that form a seal with a surface of the vertical member against the elements. The inverted U-shaped channel is not found on the brackets used to hold the lateral edges of the panels. Instead, a complicated two-part clip forms the vertical joint between adjacent panels.
The present invention provides a fastening system and bracket that alleviates the above mentioned problems by using brackets with inverted U-shaped channels on the bottom and both lateral edges of the panels. In the present design, the panels must be installed from bottom-to-top but not necessarily in any particular lateral order. This simplifies the removal of a: damaged panel. It also allows panel installation to be initiated in the middle of a wall and to proceed in both lateral directions at once. By permitting this flexibility in the installation procedure, two different crews can be working from the middle of the wall out thereby adding to the cost efficiency of the entire installation procedure. This not only allows faster installation, but it also simplifies the accurate placement of panel edges to match doorways, windows and wall corners etc. In addition, the brackets have been designed such that it is possible to remove a single damaged panel from a wall without requiring the removal of laterally adjacent panels. In addition, a pair of plastic guides positioned above the flexible wipers within the U-shaped channel offers better structural support for the panels, which result in a more accurate alignment of the panels and less movement of the panel assemblies when exposed to high winds. Furthermore, the track provided in the top of the straight of the T-shaped bracket can be used to secure a piece of angle iron to form accurate corners, and/or to secure a stiffener across the back of the panel.